Abstract
BACKGROUND: Vitamin B12 and folic acid deficiency are common in the older and are associated with several conditions including anaemia, cardiovascular disease, cognitive impairment and cancer. Evidence from in vitro studies suggests that solar radiation can degrade both vitamins in the skin. Chile is the longest country in the world running perfectly North-South making it an ideal place to study potential associations of latitude and solar radiation on vitamin B12 and folic acid deficiency.
OBJECTIVES: The objective was to examine the association between vitamin B12 and folic acid deficiencies and latitude.
METHODS: Plasma samples were collected from Chileans aged 65+ years (n=1013) living across the whole country and assayed for vitamin B12 and folic acid concentrations as part of the Chilean Health Survey 2009-2010, which is a national representative sample study.
RESULTS: Overall, the prevalence of vitamin B12 deficiency was 11.3%, with the prevalence in the North of the country being significantly greater than in the Central and South zones (19.1%,10.5%, and 5.7%, respectively; P<0.001). The prevalence of folic acid deficiency in the whole cohort was 0.7% with no difference between the 3 geographical zones. Using logistic regression analyses, vitamin B12 deficiency was significantly associated with geographical latitude (OR 0.910 [95% confidence intervals 0.890-0.940], P<0.001) and solar radiation (OR 1.203 [95% confidence intervals 1.119-1.294], P<0.001). These associations persisted after adjustments for confounders (OR 0.930, P<0.001 and 1.198, P=0.002, respectively).
CONCLUSIONS: In the Chilean population of 65+, the prevalence of vitamin B12 deficiency is associated with living closer to the Equator and solar radiation. Although degradation by solar radiation might explain this observation, further work is required to establish the potential mechanisms. In countries that routinely fortify food with folic acid, efforts to identify vitamin B12 deficiency might be more cost-efficiently targeted in areas closest to the Equator.
| Original language | English |
|---|---|
| Pages (from-to) | 8-13 |
| Number of pages | 6 |
| Journal | Journal of Photochemistry and Photobiology B: Biology |
| Volume | 140C |
| Early online date | 8 Jul 2014 |
| DOIs | |
| Publication status | Published - Nov 2014 |
Bibliographical note
Copyright © 2014 Elsevier B.V. All rights reserved.Keywords
- Vitamin B12
- Folic acid
- Deficiency
- Geographical latitude
- Solar radiation
Access to Document
- Pablo_Vitamin_B12_deficiency_Journal_Photochemistry_Photobiology_B_2014
NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Photochemistry and Photobiology B: Biology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Photochemistry and Photobiology B: Biology, Volume 140, November 2014, Pages 8–13; DOI: 10.1016/j.jphotobiol.2014.07.001 Checked for repository 28/10/2014